linux-kernel - Re: [PATCH 1/4] hugetlbfs: add arch_hugetlb_valid

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1c8b16c7-248e-b75f-96c6-eabc953c5066@intel.com>
Date:   Wed, 18 Mar 2020 16:36:56 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Mike Kravetz <mike.kravetz@...cle.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linuxppc-dev@...ts.ozlabs.org, linux-riscv@...ts.infradead.org,
        linux-s390@...r.kernel.org, sparclinux@...r.kernel.org,
        linux-doc@...r.kernel.org
Cc:     Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Heiko Carstens <heiko.carstens@...ibm.com>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ibm.com>,
        "David S.Miller" <davem@...emloft.net>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Jonathan Corbet <corbet@....net>,
        Longpeng <longpeng2@...wei.com>,
        Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH 1/4] hugetlbfs: add arch_hugetlb_valid_size

On 3/18/20 3:52 PM, Mike Kravetz wrote:
> Sounds good.  I'll incorporate those changes into a v2, unless someone
> else with has a different opinion.
> 
> BTW, this patch should not really change the way the code works today.
> It is mostly a movement of code.  Unless I am missing something, the
> existing code will always allow setup of PMD_SIZE hugetlb pages.

Hah, I totally skipped over the old code in the diff.

It looks like we'll disable hugetblfs *entirely* if PSE isn't supported.
 I think this is actually wrong, but nobody ever noticed.  I think you'd
have to be running as a guest under a hypervisor that's lying about PSE
not being supported *and* care about 1GB pages.  Nobody does that.